IE45072B1

IE45072B1 - Synthesis of 6-(d-2-phenyl-2-(4-pyridyl-formimidoylaminoacetamido)-acetamido)penicillanic acid

Info

Publication number: IE45072B1
Application number: IE1137/77A
Authority: IE
Original assignee: Pfizer
Priority date: 1976-06-03
Filing date: 1977-06-02
Publication date: 1982-06-16
Also published as: FR2367748B1; DK206577A; US4073780A; NL7704353A; DE2759395B1; DE2724551A1; GB1540347A; DE2759395C2; DE2724551C3; DE2724551B2; FR2355019B1; JPS52148094A; FR2355019A1; IE45072L; ES458313A1; BE855325A; FR2367766B1; GB1540346A; FR2367748A1; LU77464A1

Abstract

Processes for the preparation of 6-[D-2-phenyl-2-(4-pyridylformimidoylaminoacetamido)acetamido]penicill anic acid via acylation of 6-aminopenicillanic acid and derivatives thereof.

Description

Methods used to synthesise penicillins vary widely depending on the availability of starting reagents and the structure of the final product. It has now been discovered that 6-Q)-2-phenyl-2-(4-pyridylfonnimidoylaminoacetamido)acetamidoj penicillanic acid, a useful antibacterial agent, can be conveniently prepared by coupling 4pyridylformimidoylglycyl-D-phenylglyeine with 6-aminopenicillanic acid and derivatives thereof.

U.S. Patent 3,951,952 claims the product of the present invention and discloses its preparation by acylation of D-a-aminobenzylpenicillin with 4-pyridylformimidoylaminacetic acid as the acid chloride or activated ester and through the reaction of methyl 4-pyridylformimidate and 6-QD-2phenyl-2-(aminoacetamido)acetamido]penicillanic acid. ΰο7· It has now been found that the penicillin of the formula: can he synthesized by contacting a 4-pyridylformimidoylglycyl-D-phenylglycine compound of the formula: G-NHCHjCONHCHC-X NH wherein X is chloro, phenoxy, 4-chlorophenoxy, 4-nitrophenoxy, phenylthio, 4chlorophenyIthio, 4-nitrophenylthio, 2-pyridylthio, N-phthalimidoxy, N-sucJinimiQoxyifc-benzotriazoloxy, -O-C(“NR')NHR wherein R* and R are each cyclo· II hexyl or N-morpholinoethyl, or R-C-O- wherein R is selected from alkoxy having from one to four carbon atoms and t-butyl, with a 6ld aminopenicillanic acid of the formula:· ν’ Ζ wherein Ζ is hydrogen or a blocking moiety preferably selected from : .

XS1. a) -p wherein R. and.' R, are each selected from _ Xr2 alkyl having one to three carbon atoms, alkoxy having one to three carbon atoms and phenyl; b) 3,5-di-t-butyl-4-hydroxybenzyl; . c) II -CH2-Y wherein Y is selected from “CR^ wherein R-g is selected from phenyl and alkyl having cne to three carbon atoms, -CN and carboalkoxy having two to four carbon atoms; d) -N=CHR^ wherein R4 is selected from phenyl- and alkyl having one to three carbon atoms; e) Sn(Rg)2 wherein Rg is alkyl having one to four carbon atoms; f) CRgR^Rg wherein Rg and R? are each selected from hydrogen, phenyl and methyl and Rg is selected from phenyl, 4-methoxyphenyl, 4-nitrophenyl and methyl, provided that when Rg and R? are each methyl, Rg is also methyl; g) -CH2CRgR10R1^ wherein Rg is selected from bromo, chloro and iodo and R^Q and R-q are each selected from hydrogen, bromo, chloro and iodo; and h) Si(CH2)2R^2 wherein R^2 is selected from methyl and 6-aminopenicillanoyloxy, in a reaction inert solvent at a pH of 3.5-8 ahd reaction temperature of 0 to -15°C., followed by removal of the blocking moiety, Z. - 4 4S072 A preferred feature of the present invention is the acylation of the· aforementioned 6-aminopenicillariic acid wherein Z is as defined,with 4-pyridylformimidoylglycyl-D-phenylglycine of the aforementioned formula wherein X is If R-C-O- wherein R is alkoxy having from one to four carbon atoms.

Si A second1 process leading to the penicillin of the formula: comprises contacting a 4-pyridylformimidoylglycyl-D-phenylglycine compound of the formula: NH c-nhch2conhchcox wherein X is chloro, phenoxy, 4-chlorophenoxy, 4-nitrophenoxy, phenylthio, 4chlorophenylthio, 4-nitrophenylthio, 2-pyridylthio, N-phthalimidoxy, N-suc10; cinimidoxy, 1-benzotriazoloxy, -O-C(»NR')NHR wherein R' and R are each cyclo-, tl hexyl or N-morpholinoethyl, or R-C-O- wherein R is alkoxy haying one to four carbon atoms and t-butyl, with a 6aminopenicillanie acid derivative of the formula: - 5 Qrl* in a reaction-inert solvent, pH of 3.3-8 and reaction temperature of -10 to -5°C., followed by aqueous hydrolysis of the saccharimide group at a pH of 8-8.5. A preferred feature of this second process invention comprises the acylation of the aforementioned 6-aminopenicillanic acid derivative with a.4pyridylformimidoylglycyJ-D-phenylglycine compound of the aforementioned form/ . 0 ula wherein X is R-C-0- wherein R is alkoxy having from one to four carbon atoms.

Also’ considered within the scope of the present invention are the intermediate blocked derivatives of 6-[D-2-phenyl-2(4-pyridyl£ormifliidoylamino icetamido)acetamido]penicillanic acid compounds wherein Z is as defined, but Other than hydrogen.

Although acylation reactions of 6-aminopenictllanic acid are quite well known, it Is particularly surprising that under the reaction conditions of the instantly claimed processes, that there is no appreciable reaction of the derivatized 4-pyridylformiaidoylglycy1-D-phenylglycine with the more basic amidine portion of the side chain reactant.

In addition, there appears to be no racemization of the D-phenylglycine portion of the reactant side chain via intramolecular formation of an 2C oxazolone derivative.

As one skilled in the art can readily appreciate, the u-carbon atom oc the penicillin side chain to which the 4-pyridylformimidoylaminoacetamido moiety is attached is an asymmetric carbon atom allowing for the existence of two optically active isomers, the D- and L-diastereoisomers, as well as the racemate, DL form. In accord with previous findings concerning the activity of such penicillins possessing asymmetric a-carbon atoms, the compound of th present invention possessing the D-configuration is more active than that of the L-configuration and is the configuration to which the present applicatio is restricted.

. Further, it is noteworthy to mention while considering asymmetric centers, that there are several in the 6-aminopenicillanic acid nucleus, the basic building block from which the compounds of the present invention are derived. These potential additional isomers are not significant in this instance since the 6-aminopenicillanic acid employed leading to the product of this process invention is that which is produced by fermentation and is consistently of one configuration. - 7 The first process reaction of the present invention is depicted in the following scheme: NH wherein X and Z are as previously defined. - 8 In general, the acylation is carried put in a reaction-inert solvent,· said solvent being one which appreciably solubilizes the reactants without reacting to any great extent with either the reactants or the products under the reaction conditions. It is preferred that these solvents be highly polar, · aprotic solvents which are miscible with water and will not freeze or solidifyι at temperatures which represent the low end of the reaction temperature range of the claimed reaction process. Such solvents or mixtures thereof include 1aethyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide and hexamethylphosphoramide. The preferred solvents are 1-methy1-2-pyrrolidorU and dimethylformamide.

The molar ratio of reactants is not a critical factor in the claimed . ι reaction process. The use of a slight excess of the 6-aminopenicillanic acid derivative, up to as much as ten percent, aids in the completion of the reactants and offers no serious problem in isolating the desired product in puri151 fled form.

Reaction time, too, is not critical, and ls inherently dependent on j concentration, reaction temperature and reactivity of the starting reagents. ( 'i Under the reaction-temperature conditions of about 0 to -15°C. the reaction is usually complete in 30 minutes to 3 hours.

I ! ' The preferred reaction temperatures are those which allow the reaction to proceed at a practical rate without resulting in thermal degradation of the starting reagents or products of said process. Accordingly, temperatures of 0 to -15’C. are operable.

The order of the addition of the reactants is not critical. Because I ^ of the labile nature of the various derivatives of 4-pyridylformimidoylglycylD-phenylglycine, it is preferred that these reactants not be isolated.

Consequently, it is preferred that the appropriate derivative be prepared in situ from the corresponding 4-pyridylformimidoylglycyl-D-phenylglycine. It is further preferred that the requisite derivative in an appropriate solvent of the aforementioned description be added to 6-aminopenicillanic acid derivative 51' in an appropriate solvent or mixture of said solvents.

As previously mentioned, the claimed process is conducted at a pH of 3.5-8. This is most conveniently carried out by employing the appropriate » 4-pyridylformimidoylglycyl-D-phenylglycine derivative as some general acid addition salt. The preferred salts include the sulfate salt, £-toluenesulfonic acid salt, the hydrobromide salt, the phosphate salt and the hydrochloride salt.

The conversion of the 4-pyridylfonnimidcylglycyl-D-phenylglycine to the appropriate detivate suitable for acylation of the requisite 6-aminopenicillanic acid of the previously mentioned formula is carried out in a manner well-known to one skilled in the art. θ II In preparing those starting reagents wherein X is R-C-O- and R is alkoxy or t-butyl, 4-pyridylformimidoylglycyl-D-phenylglycine is contacted with II about an equimolar amount of the appropriate acid chloride, R-C-Cl, wherein R is as previously defined. The solvents suitable for the preparation of the intermediate mixed anhydrides are those which are also useful in the claimed processes. Reaction temperatures of about -15ό0. are preferred, with a corresponding reaction time of 15-20 minutes. The preferred mixed anhydrides for the acylation of the 6-aminopenicillanic acid and derivatives thereof are those wherein R is ethoxy.

In synthesizing the acylating reagent wherein X is chloro, 4-pyridyl£ormimidoylglycyl-D-phenylglyeine is reacted with thionyl chloride in one or more of the solvents previously described as suitable for the claimed processes: The reaction temperatures of -15 to -20’ are preferred, with a corresponding Si reaction time of 45-60 minutes.

Preparation of those acylating reagents wherein X is -O-C(”NR')NHR where R' and R are each cyclohexyl or N-morpholinoethyl is carried out by contacting 4-pyridylformimidoylglycyl-D-phenylglyc.ine with the appropriate carbodiimide, R'-N»C»N-R. Approximately equimolar amount of reactants are 1Q| employed, said reaction being conducted in one or more of the solvents operable in the claimed processes. The reagent is generally formed at ambient temperatures requiring only a few minutes reaction time. The solution of the acylati-i- agent is subsequently cooled to 0 to -15°C. for the reaction with the requisite 6-aminopenicillanic acid or derivative thereof. lit For the synthesis of those acylating agents wherein X is phenoxy, 4chlorophenoxy, 4-nitrophenoxy, phenylthio, 4-chloropbenylthio, 4-nltrophenylthio, 2-pyridylthio, N-phthalimidoxy, N-succinimidoxy or 1-benzotriazoloxy, it is preferred that they be prepared through either the mixed anhydride or the intermediates wherein X is -O-C(“NR')NHR both of whose preparation has pre2^ vlously been discussed. In practice, after the mixed anhydride or isourea has been prepared In situ, the appropriate N-hydroxy compound, phenol or thiol is added in about equimolar amounts, resulting in the formation of the corresponding activated ester. Alternatively, all three reactants, 4-pyridylformimidoylglycyl-D-phenylglycine, the carbodiimide and the N-hydroxy compound, - 11 <12072 ’j phenol or thiol, can be added all at the same time. The solvents preferred for. the preparation of the activated ester acylating agents are the same suited to the processes of the present invention. Ambient temperatures are preferred fori 1 J the formation of the acylating compound, with a reaction time of 15-20 minutes.5.. The aforementioned acylating agents can be used to acylate 6-aminopenicillanic acid directly (wherein Z is hydrogen) or, alternatively,a derivative of 6-aminopenicillanic acid wherein Z is other than hydrogen as previously d defined. These other derivatized forms of ό-aminopenicillanic acid are well ii known to those skilled >in the art and are relatively easy to prepare, Fol* . . · ' . * · lowing the acylation of these'derivatives, the blocking group, Z, is subsequently removed in a manner dictated by the nature of said Z group. “. j The first of these blocking groups is the phosphine ester, the preparation of which is taught in W. German application 2,218,209. Of those definitions for K . and R. variables for the group -P^^l , methoxy is especially - 2 K2 preferred. The preferred solvent is dimethylformamide and the preferred reaction' temperature for the acylation reaction employing this 6-aminopenicillanic acid derivative is 0°C. Removal of the blocking group is conveniently carried 1 out by additon of water.

A second blocking group is that wherein Z is 3,5-di-b-butyl-4-hydroxy20. benzyl, the preparation of this 6-aminopenicillanic acid derivative being taught I in W. German application 2,033,493.- The preferred solvent for this acylation reaction is dimethyLformamide. The reaction temperature is -10’C. with a corresponding reaction time of 20-30 minutes. Following the acylation of the 6aminopenicillanic acid derivative, the blocking group is removed by aqueous |J hydrolysis at pH 8.0. - 12 The third type of blocking moiety suitable for 6-aminopenicillanic acid are those wherein Z is CH2-Y where Y is as previously defined. The preparation of these 6-aminopenicillanic acid derivatives is taught in Acta. Chem. Scand., 21, 2210 (1967). It is preferred that these derivatives he acylated in the preferred reaction-inert solvent of dimethylformamide at a reaction temperature of -10eC. for a reaction time of about 30 minutes. Removal of the blocking group is done by treatment with iodide ion, thiocyanate or mercaptan ion or an amine; the preferred removal is with potassium thicphenomide. The ti preferred Y for this blocking group is -C-R^ wherein R^ is phenyl. 1C The fourth type of blocking moiety is that wherein Z is -NaCHR^ wherein is as previously defined. The synthesis of these 6-aminopenicillaniC intermediates is taught in £. Chem. Soc., 1917 (1971c). Dimethylformamide is , the preferred solvent for the acylation of these derivatives, emrloying a ; reaction temperature of 0°C. and reaction time of 30-45 minutes. At the com151 pletion of the acylation reaction the blocking moiety can be removed by treatment with a nucleophile such as mercaptide, thiocyanate or iodide ion. The prer ferred removal is with sodium iodide. The preferred for this blocking moietjr is phenyl.

The fifth type of' blocking group employed in the claimed process is that where Z is Srt(R5)g, said 6-aminopenicillanic acid derivatives having been prepared according to the method as reported in Acta. Chem. Scand.. 22, 367 (1968). Acylation of these blocked 6-aminopenicillanic acid derivatives is preferably carried out in dimethylformamide as the reaction solvent, employing a reaction temperature of -5°C. and a corresponding reaction time of 30-45 minutes. The blocking group can be conveniently removed using a mercaptide or thiocyanate ion as the nucleophile; the preferred reagent for removal is potassium thiophenosd.de. The preferred Rg for this blocking moiety is n-butyl.

The sixth useful blocking group, Z, on the 6-aminopenicillanic acid reagent is -CRgR^Rg wherein Rg, R? and Rg are as previously defined. These derivatives are prepared by the method as taught in J. Med. Chem., 11, 929 (1968). Especially preferred in the process are those intermediates wherein Rg and Ry are each hydrogen and Rg is 2-methoxyphenyl. The acylation reaction is conveniently carried out in the preferred solvent, dimethylformamide, at a reaction temperature of -10°C. and reaction· time of 30-45 minutes. When the reaction is complete, the blocking moiety can be removed by hydrolysis with hydrofluoric acid or by catalytic hydrogenation using palladium on charcoal.

Both these latter methods of removal are preferred.

The seventh type of blocking group useful in the claimed process is that wherein 2 is -CHjCRgS^gR^ where Rg, R^q and R^ are as indicated. These 6-aainopefiicillSnic acid intermediates ate prepared by the procedure of West German Application 1,937,962. The preferred solvent for the acylation of thesei derivatives is dimethylformamide, the preferred reaction temperature being -5°c!. with a reaction time of 30-60 minutes. The blocking group, wherein the preferred - 14 a £>0 7 2 definition of Rg, R^ and R^ are each chloro, is removed by electrolytic reduc· cion.

The eighth type of blocking moiety is that wherein Z is -SiCCHj^Rp wherein R^ is as previously indicated; the preferred R^ is CHy Acylation of 5j' these blocked 6-aminopenicillanic acid derivatives is conveniently carried out in dimethylformamide, with a reaction temperature of -10°C. and reaction time of 60-90 minutes. The blocking group is easily removed by simple water hydrolysis. Such blocked derivatives of 6-aminopenicillanic acid are prepared according to Che procedures in Ann., 673, 166(1964). iQj As previously mentioned, the claimed process can also· be applied to the acylation of che unblocked 6-aminopenicillanic acid wherein Z is hydrogen. The preferred solvent for this ecylation is l-methyl-2-pyrrolidone and the reaction temperature should be maintained at about -10°C. Employing these cont ditions, the reaction time is about 15-20 minutes. 15jf In all the aforementioned acylation reactions the desired product, 6-[D-2-phenyl-2-(4-pyridylformimidoylaminoacetamido)acetamldo]penicillanic acidl, is conveniently isolated by the precipitation of the zwitterion with the addition of methanol to the reaction mixture after the blocking group has been removed. As one skilled in the art can readily appreciate, very low concentra2(j tion (g./ml.) of the product in the reaction mixture makes isolation by addition of a precipitating solvent very inefficient. Accordingly, it is preferred! that when a dilute solution of 1-27! of the product in the reaction mixture are employed, that the mixture be concentrated such that higher concentrations are ' obtained. In general, a concentration of the product in the reaction mixture 2^j of 10% or better result in excellent recovery by methanol precipitation. 0bi viously, when 2 is hydrogen no removal prior to isolation is necessary. Such precipitation of the product should be carried out as near as possible to its isoelectric point of pH 5.5. Depending on the pH of the solution after de- ; blocking, hydrochloric acid or aqueous sodium hydroxide solution can be added 3$ to adjust the pH to said isoelectric point.

I 4.a ο τ 3 A second process of the present invention, useful for the synthesis of 6-[Q-2-phenyl-2-(4-pyridylformimidoylhminoacetamido)AcetamidoJpenicillanic acid, is depicted in the following scheme: NH C=0 wherein X is as previously defined. -> -16 - v - αΰογ3 The acylation is carried out, as indicated in the first process, in a. reaction-inert solvent, said solvent being one which appreciably solubilizes the reactants without reacting to any great extent with either the reactants or the products under the reaction conditions. Again, it is preferred that these sol5 vents be highly polar, aprotic solvents which are miscible with water and will ' not freeze or solidify at temperatures which represent the low end of the reaction temperature range of the claimed reaction process. Such solvents or mixtures thereof include l-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide and hexamethylphosphoramide. The preferred solvent ioji is dimethylformamide.

The molar ratio of reactants is not a critical factor in the claimet reaction process. The use of a slight excess of the 6-aminopenicillanic acid saccharimide derivative, up to as much as ten percent, aids in the completion of the reactants and offers no serious problem in Isolating the desired product l ·! in purified form.

I Reaction time, too, is not critical, and is inherently dependent on concentration, reaction temperature and reactivity of the starting reagents. Under the reaction-temperature conditions of about -10 to -5°C., the reaction is usually complete in 30-60 minutes. 2(J! The preferred reaction temperatures are those which allow the reaction to proceed at a practical rate without resulting in thermal degradation of the starting reagents or products of said process. Accordingly, temperatures of -10 to -5°C. are operable, with a preferred temperature of -5°C.

The order of the addition of the reactants is not critical. As 2^ previously discussed, because of the labile nature of the various derivatives of 4-pyridylformifflidoylglycyl-D-phenylglycine, it is preferred that these reactants not be isolated. Consequently, it is preferred that the requisite derivative be prepared in situ from 4-pyrldylformimidoylglycyl-D-phenylglycine; ΰ Ο 7Ζ · In addition, it is preferred that the requisite derivative in an appropriate solvent of the aforementioned description be added to the 6-aminopenicillanic ι i acid saccharimide derivative in an appropriate solvent or mixture of solvents.

Following the completion of the acylation reaction, the blocking ' saccharimide group is removed by adjusting the pH of the reaction mixture to [ ’ 8-8.5 with a suitable inorganic base and allowing the mixture to stir at room temperature for about 3-4 hours.

Isolatioti.of the desired product is achieved as in the first process 'by precipitation of the zwitterion at the isolated point of 5.5. Aqueous hydro 101! chloric acid is'used to lower the pH to this preferred pH.

The starting 6-aminopenicillanic acid saccharimide derivative is synthesized by the procedure of British Patent 1,281,952.

Also included Within the scope of the present invention as useful intermediates are the intermediate blocked derivatives of 6-[D-2-phenyl-2-(4lsfj pyridylformimidoylaminoacetamido)acetamido]penicilianic acid of the formulae: wherein Z is as previously described, hut other than hydrogen» - 18 Among these useful intermediates which are especially preferred are ; those related to I where 2 is -PR^ and R2 where R^ and R, are each methoxy; Z o : ιι I .‘.s 3,5-di-C.-butyl-4-hydroxybenzyl; Z is -CHjCRg where Rg is phenyl; Z is -N»CHR^ where R^ is phenyl; Z is Sn(Rj)g where R^ is n-butyl; Z is -CRgR^Rg where R& and I R? are each hydrogen and Rg is £-me thoxy benzyl; Z is -Cl^CRgR^R.^ wherein Rg, R^g and R^ are each chloro; and Z is -SiiCHj^Rj^ where R^ is CHg. Also preferred is the compound of formula II.

The penicillin described herein exhibits in vitro activity against a wide variety of micro-organisms, including both gram-positive and gram-negative, 1C bacteria. Its useful activity can readily be demonstrated by in Vitro tests l against various organisms in a brain-heart infusion medium by the usual two- ί fold serial dilution technique. The in vitro activity of the herein described compound renders it useful for topical application in the form of ointments, creams and the like, or for sterilization purposes, e.g., sick-room utensils.

·? This penicillin is also an effective antibacterial agent in vivo in animals, including man, via the parenteral route of administration.

Obviously, the physician will ultimately determine the dosage which will be most suitable for a particular individual person, and it wiljvary with the age, weight and response of the particular patient as well as with the 2>)l nature and extent of the symptoms and the nature of the bacterial infection being treated.

Having full regard for the foregoing factors, it is considered that . an effective'daily parenteral dose of 25-100 mg./kg. per day, with a preferred) range of about 20-75 mg./kg. per day, will effectively alleviate the symptoms 2^i of the infection. These values are Illustrative, and there may, of course, be individual cases where higher or lower dose ranges are merited.

The following examples are provided solely for the purpose of illustration. - 19 EXAMPLE 1 6- [p-2-Phenyl-2-(4-pyridylformimidoylaminoacetamido)acetamido] penicillanic acid pTo a solution of 10.32 g. of 4-pyridylformimidoylglycyl-D-phehylglycine in 125 ml. of dimethylformamide at -15°C. is added 3.56 g. of ethyl chloroformate, and the resulting solution, after stirring at -15°C. for 15 min., is cooled to -20°C.

To a suspension of 7.13 g. of 6-aminopenieillanie acid in 60 ml. of water neutralized to pH 7.8 with a dilute aqueous sodium hydroxide solution and cooled to 5°C. is added 40 ml. of dimethylformamide. The solution is then cooled to -10°C. and the solution of the dipeptide mixed anhydride is added slowly over a 5 min. period. Cooling is continued during the additon such that the temperature remains at -10 — 1°C. The reaction mixture is allowed to stir at -10°c. for an additional 15 min., and is then allowed to warm to room temperature. The clear solution is concentrated in vacuo at 35°C. to approximately 135 ml., and is diluted with 400 ml. of methanol. After stirring over night, the resulting precipitate is filtered, washed with methanol and dried, 12.97 g. (74% yield).

The product is indistinguishable via infrared and nuclear magnetic resonance spectroscopy from that prepared by the processes of U.S. #=3,951,952.

Similar results are obtained when methyl, i-propyl and n-butyl chloroformates are employed in place of ethyl chloroformate.

EXAMPLE 2.

To a solution of.1,25 g. of 4-pyridylformlmldoylglycyl-Dphenylglycine in 25 ml* of dry dimethylformamide cooled to -15pc. is added 485 mg. of pivaloylchloride. After allowing the reaotion mixture to stir for 15 min. at -10°C., 950 mg. of 6aminoperticillanic acid in 20 ml. of water adjusted to pH 7.8 and at a temperature of 5°c. is added to the dimethylformamide solution. The temperature,· which rose to 7°C. during the addition, was held at 0°C. for 15 min,and then allowed to warm to room temperature over a 30 min. period.

High-pressure-liquid-chromotography of an aliquot indicates a yield of 1.17 g. (58% yield) of the desired product, 6-[p-2-phenyl2-(4-pyridylformimidoylaminoacetamido)acetamido] penicillanic acid, identical with the product of Example 1.

EXAMPLE 3 A suspension of 2.16 g. of 6-aminopenicillanic acid in 40 ml. of methylene chloride is treated with 1.08 g. of triethylamine and allowed to stir at room temperature until a clear solution results. The solution is cooled co 0°C. and 1.28 g. of dimethoxychlorophosphine is added.

After stirring for 15 min. a solution of the mixed anhydride, formed by adding 1.18 g. of ethyl chloroformate to 3.12 g. of 4-pyridylformirnidoylglycyl-D-phenylglycine in 40 ml. of dimethylformamide cooled to -15°C., is added over a five minute period while the reaction temperature is maintained at 0 to -5°C. Stirring is continued for an additional 30 min. followed-by dilution of the reaction with 20 ml. of water. The hydrolyzed reaction mixture is stirred for 20 min. and the aqueous layer separated and treated with 200 ml. of methanol. The product, which cryscallizes from the aqueous-methano solution, is identical to that isolated in Example 1. - 21 EXAMPLE 4 The.following pairs of mixed anhydrides and phosphine penicillanic acid esters prepared by the procedures of Examples 1 and 2, and 3, respectively provide the desired product, 6-[D-2-phenyL-2-(4-pyridylformiraidoylaminoace5 tamido)acetamido]penicillanic acid: 4-pyridylformiraidoylglycyl-D-phenylglycine methoxyformic anhydride and di-n-propyiphosphinyl 4-aminopenicillanate; 4-pyridylformimidoylglycyl-D-phenylglycine _i-propoxyformic anhydride and diphenylphosphinyl 4-aminopenicillanate; 4-pyridylformimidoylglycyl-D-phenylglycine n-butoxyformic anhydride and dimethoxyphosphinyl 4-aminopenicillanate; 4-ρyridylformimidoylglycyl-D-ph'l·nylglycine pivalic anhydride and dimethoxyphosphinyl 4-aminopenicillafiate; 4-pyridylformimidoylglycyl-D-phenylglycine ethoxyformic anhydride 15 and di-n-propylphosphinyl 4-aminopenicillanate; and 4-pyridylformimidoylglycyl-D-phenylglycine pivalic anhydride and diphenylphosphinyl 4-aminopenicillanate; -,22 «2072 EXAMPLE 5 A. S-Pyridylformimidoylglycyl-D-phenylglycine ethoxyformic anhydride Xn a manner similar to Example 4, a solution of 3.12 g. of 4-pyridylformimidoylglycyl-D-phenvlgiycine in 40 ml. of dimethylformamide cooled to -15°t. is treated with 1.18 g. of ethyl chloroformate. After stirring for 15 min. ac -15“C. the solucion is further cooled, to -50’C.

B. 6-[D-2-Pheny1-2(4-pyridylformimldoylarninoacetamido)acetamidoJpenicillanic acid A solution of 5 g. of 6-aminopenicillanic acid, 3',5'-di-e_-butyl*-4'10 hydroxybenzyl ester in 50 ml. of N-methyl-2-pyrrolidone at -10’C. is treated with a dimethylformamide solution of 4-pyridylforraimidoylglycyl-D-phenylgl'ycinej ethoxyformic anhydride (Example 5A). After stirring 20 min. at -10° to -15°C. che cooling bath is removed'and a solution of 1.82 g. of sodium 2-ethylhexanoatje . in 20 ml. of methanol is added. Stirring is continued for 3 hrs. at room tem15 perature followed by the addition of 200 ml. of methanol. The product, which crystallizes, is identical with that isolated from Example 1. - 23 EXAMPLE ft The following mixed anhydrides, when reacted with 6-aminopenicillanic; acid, 3',5'-di-c-butyl-4-hydroxybenzyl ester according to the procedure of Example 5B, provides the desired produce, 6-[D-2-phenyl-2-(i-pyridylformirai5 doylaminoaceeamido)acetamido]penicillanic acid: • A-pyridylfortnimidoylglycyl-D-phenylglycine me thoxy formic anhydride; i-pyridylformimidoylglycyl-D-phenylglycine i-propoxyforntic anhydride 4-pyridylf0rmiraidoyiglycyl-D-phenylglycine n-butoxyformie anhydride; and 4-pyridylfarmimidoyiglycyl-D-phenylglycine pivalic anhydride.

EXAMPLE 7 To an ice-cooied suspension of 4.9 g. of 6-aminopenicillanic acid, phenacyl ester benzenesulfonic acid halt in 50 ml, of dimethylformamide is added 1,1 g. of triethylamine.' To the resulting solution, which is cooled to -5* to -lO’C,, is added slowly the mixed anhydride as prepared in Example 5A.

Af ter-stirring in the cold for 30 min., the reaction mixture is diluted with 100 ml. of water and extracted with ethyl acetate. The organic extracts are combined, washed with water, dried over sodium sulfate and concentrated to dryness. The residue is dissolved in 40 ml. of dimethylformamide and treated with a solution of 1,2 g. of potassium thiophenoxide in 10 ml, of dimethylfor.maaide. After stirring at room temperature for one hour the pH of the solution is adjusted to 5.5 by the addition of 2N hydrochloric acid followed by che addition of 200 mi. of methanol. The desired product which slowly crystallizes from: the solution is identical in all respects to che 6-[b-2-phenyL· 2-(4-pyridyl£o,rmimidoylaainoacetamido)acetamidoIpenicillanic acid formed in previous examples. - 24 EXAMPLE 8 αίϊο?2 6-[D-2-Pheny1-2-(4-pyridylformiraidoylarainoaeetamido)acetamido]penicillanic acid, identical with that prepared in preceeding examples, is synthesized by following the procedure of Example 7 employing the following pairs of reactants: 4-pyridylforntiaidovlglycyl-D-pheny lglycine me thoxy formic anhydride and 6-aminopenicillanic acid, acetonyl ester; 4-pyridylforaimidoylglycyl-D-phenylglycine .n-butoxyformic anhydride and 6-aminopenicillanic acid, cyanomethyl ester; 4-pyridylformimidoylglycyl-D-phenylglycine athoxyformic anhydride and 6-aminopenicillanic acid, methoxycarbomethyl ester; 4-pyridylformimidoylglycyl-D-phenylglycine pivalic anhydride and 4aminopenicillanic acid, phenacyl ester; 4-pyridylformimidoylglycyl-D-phenylglycine i-propoxyformic anhydride 15 and 4-aminopenicillanic acid, propionylmethyl ester; 4-pyridylformimidoylglycyl-D-phenylglycine ethoxyformic anhydride and 4-aminopenicillanic acid, i.-butyrylmethyl ester; ι 4-pyridylformimidoylglycyl-D-phenylglycine pivalic anhydride and 4-aminopenicillanic acid, n-propoxycarbomethyl ester; 4-pyridylformimidoylglycyl-D-phenylglycine n-butoxyformic anhydride and 4-aminopenicillanic acid, cyanomethyl ester; and 4-pyridylformimidoylglycyl-D-phenylglycina pivalic anhydride and 4-aminopenicillanic acid, acetonyl ester.

EXAMPLE 9 A solution of 4.9 g. of 0-(6-aminopenicillanoyl)benzaldehyde oxime jytoluenesulfonic acid salt in 50 ml. of N-methyl-2-pyrrolidone cooled to 0*C. is treated with 1.1 g. of triethylamine and then 4-pyridyIfomimidoylglycyl5 D-phenylglycine ethoxyformic anhydride in 40 ml. of the same solvent prepared according co the procedures of Example 5A. After stirring in the cold for 30 min. the solution is warmed to room temperature and 1.5 g. of sodium iodide1 in 20 ml. of acetone is added. Stirring is continued for 3 hrs. followed by dilution of the solution with 200 ml- of methanol and adjustment of the pH 101 to 5.5 with 2N hydrochloric acid. The precipitated product, when filtered, is identical to 6-[D-2-phenyl-2-(4-pyridylfotmimidoylaminoaceeamido)acetamldo]i : penicillanic acid prepared in Example 1.

EXAMPLE 10 In a manner similar to Example 9, the following 6-aminopenicillanic 15 ) acid ester and anhydrides are reacted to give 6-(D-2-phenyl-2-(4-pyridylformimidoylaminoacecamido)acecamido]penicillanic acid, Identical to that preparedl in preceedlng examples: - 26 <ίΰο7 tt 0- -o-c-och3 0- 0 ..()-C-OC4Hg 0- 0 -0-C-OC3H7 0- 0 -O-CC(CH3) CH3- 0 -O-C“OC2Hs ch3- 0 -o-cc(ch3).C2H5~ ό -OCC(CH3)3C2H5- 0 -O-C-OCHj n-C3H7- 0 -O-C-OCH3 n-C3H7- 0 ~)-C-0C,Ho 4 9 >c3h7- 0 ~>-C-OC,tl, J / EXAMPLE 11 To a solution or 5.0 g. of tri-n-butyltin 6-aminopenicillinate in - 50 ml. of dimethylacetamide cooled to -5°C. is added a solution of 4-py'ridylformimidoylglycyl-D-phenylglycine ethoxyformic anhydride as prepared in 5 Example 5A. After stirring in the cold for 30 min., the reaction solution is allowed co warm to room temperature and is subsequently treated wich 1.62 g. of potassium.thiophenoxide. After stirring for 30 min. at room temperature, the solids are filtered and the filtrate diluted with 200 ml. of methanol.

The crystallized material, after filtration, provided the desired 6-[D-2-phenyir .- 2-(4-pyridylformimidoylaminoacetamido)acetamido]penicillanic acid product, identical with that formed in Example 1.

EXAMPLE 12 Following the procedure of Example 11, and starting with indicated pairs of appropriate.reactants, 6-[D-2-phenyl-2-(4-pyridylformimidoylamino15 acetamido)acetamido]penicillanic acid, identical with that formed in Example 1. is prepared: 4-pyridyiformimidoylglycyl-D-phenylglycine ethoxyformic anhydride and trimethylcin 6-aminopenicillinate; 4-pyridylformimidoylglycyl-D-phenylglycine pivalic anhydride and 20 triethyltin 6-aminopeniciliinatej 4-pyridylformimidoylglycyl-D-phenylglycine methoxyformic anhydride and tri-jl-propylcin 6-aminopenicilHnate; - 28 a· «y-y-— <ϊίϊ07;3 4-pyridylformimidoylglycyl-D-phenylglycine n-butoxyformic anhydride and tri-L-butyltin 6-aminopenicillinate; 4-pyridylformimidoylglycyl-D-phenylgJvcine _i-propoxy formic anhydride and tri-L-propyltin 6-aminopenicillinate; 4-pyridylformimidoylglycyl-D-phenylglycine pivalic anhydride and tri-s-butyltin 6-aminopenicillinate; and 4-pyridylformimidoylglycyl-D-phenylglycine ethoxyformic anhydride and tri-£-propyltin 6-aminopenicillinate.

EXAMPLE 13 A solution of 4-pyridylformimidoylglycyl-D-phenylglycine ethoxyformicj anhydride, prepared according to the procedure of Example 5A, is added over a 5 min. period to a solution of 3.3 g. of 6-aminopenicillanic acid, £methoxybenzyl ester in.40 ml. of dimethylformamide cooled to -10“C. Stirring is continued in the cold for 30 min. followed by the addition of 200 ml. of IS water. The pH is subsequently adjusted to 6.0 and the solution washed twice with methyl t-butyl ketone. The pH of the aqueous phase is then lowered to 2.0 and extracted (3x) with a 52 dioctyl sulfosuccinic acid in methyl i^butyl ketone. The organic phase is separated, washed with dilute hydrochloric acid and layered with water, the pH of which is adjusted to 6.0. The aqueous layer is separated and lyophylized to give the crude intermediate ^-methoxybenzyl ester of 6-[D-2-phenyl-2-(4-pyridylformimidoylaminoacetamido)acetamidojpenicillanic acid hydrochloride salt. - 29 S ' ' . α2073 . ; The crude ester hydrochloride salt is added to 100 ml. of acetone containing 10 g. of anhydrous hydrogen fluoride and the mixture allowed to stir at 0°C. for one hour. Most of the solvent is removed at O’C. under reduced pressure and the residue dissolved in 25 ml. of water. The pH of the aqueous solution is raised to 5.5 with a 2ίί sodium hydroxide solution and created with decolorizing charcoal. The filtrate, is treated with 25 ml. of dimethylformamide and 200 ml. of methanol. The product which crystallizes is identical to 6-[D-2-phenyl-2-(4-pyridylformimidoylaminOacetamido)acetamido]penicillanic acid, the product of Example 1.

EXAMPLE 14 In a manner similar co Example 13, the following 6-aminopenicillanic acid ester and anhydrides are reacted to give 6-[D-2-pheny1-2-(4-pyridylformimidoylaminoacetamido)acetamido]penicillanic acid, identical to that prepared in. Example 1: Hn. ^cx-NHCH2C0NHCH-C0i 'NH \ S CH MX CH, co2ii S ο 7 2 X 0 II CH3- CH3- CH3- -O-C-OC,H. 2 3 0 II ch3- ch3- ch3- -O-CC(CH3>3 0 II Η- ch3- 4-CH3OC6H4- -0-C-OCH3 0 II Η- CH3- 4-CH,0C,H,~ 3 6 4 -O-C-OC3H7 0 II ch3- ch3- 4-CH3<)Cj.Hr -O-C-OC2H5 0 II ch3- CHj- 4-CH3OC6H4- -o-c-oc4h9 0 II Η- H-4-NO2C6H4 -O-C-OC,H5 0 tf Η-C6H5“C6H5 -O-C-OC2H5 0 tl Η-C6H5“ W -O-CC(CH3)3 0 If °6Η5-C6H5‘C6H5“ -O“CC(CH3)3 0 tfC6H5- WC6H5- -0-C-OCH3 0 IIC6H5” w 4-CH3OC6H4- -O-C-OC3H7 0 IIC6H5-CA 4-NO2C6H4- -O-CC(CH3)3 0 II Η- CH3- 4-NO2C6H4- -O-C-OC2H5 0 II Η- ch3- 4-N°2C6V -O-C-OCH3 EXAMPLE 15 A solution of 3.48 g. of 6-aminopenicillanic acid, S,3,3-crichloroethyl ester in 40 ml. or dimethylformamide cooled to -10°C. is treated dropwise over a 5 min. period with a dimethylformamide solution of 4-pyridylforI ’ mimidoylglycyl-D-phenylglycina ethoxyformic anhydride prepared according to the procedure of Example SA. After stirring for 30 min. at -5 to -10’C., the reaction mixture is diluted with 20 ml. of water and poured into the cathode side of a divided cell preparative electrolysis apparatus. The anode compartment is filled with 0.1M sodium chloride solution containing 1 g. of hydrazine hydrochloride. Plate graphite anode aqd cathode electrodes (2.5 x 4 cm) were introduced, and the cathode adjusted to -1.5 vc (vs. S.C.E.) using a Princeton Applied Electronics Model 373 potentiostat. Constant potential electrolysis is carried out'until che current has fallen co 52 of its original value. During this time period the pH of the cathode compartment is maintained at 5.5 and the interior temperature at 20°C. A total'of 650 milliamps is consumed during the electrolysis period of 3 hrs.

The contents of the cathode compartment is decanted and the solution treated with 200 ml. of'methahol. The solution, on standing, deposits a crystalline material identical with product from Example 1.

Similarly, reduction results were obtaihed by treating the crude trichlotoethyl ester.intermediate in solution with sufficient acid to provide a pH of 1.0, followed by addition of 1 g. of zinc dust at 0“C. fot 1 hr. - 32 / α « Ο 7 3 EXAMPLE 16 Using Che electrolytic reduction procedure of Example 15, the following esters are employed as starting materials for the synthesis of 6-[D~2phenyl-2-(4-pyridyIformiaidoylaminoacetamido)acetamido]penicillanic acid: 22 ‘TO Cl H H I . H H Cl Cl H Cl Br H Br I H Cl Br Br Cl Cl Br Cl X H Cl Cl I Br Br H Br Br Br EXAMPLE 17 The procedure of Example 13 is repeated. One gram of the intermediate 6-[D-2-phenyl-2-(4-pyridylformimidoylaminoacetamido)acetamidoJpenicillanic acid, jj-methoxybenzyl ester hydrochloride in 10 ml. of water and 20 ml. of dimethyls’ rormamide is treated with 2. g. of 102 palladium on charcoal and the resulting mixture shaken in a hydrogen atmosphere at atmospheric pressure. After the theoretical amount of hydrogen is absorbed, the spent catalyst is filtered and the filtrate adjusted to pH 5.5 and diluted with 100 ml. of methanol. After crystallization,there is obtained 6-[D-2-phenyl-2-(4-pyridylformimidoylamino1C1 acetamido)acetamido]penicillanic acid, identical with that prepared in Example 1.

In a similar manner, the intermediate ester products of Example 14 are hydrogenated co give the desired product, 6-[D-2-phenyl-2-(4~pyridyifotmimidoylaminoacetamido)acecamdio]penicillanic acid. /ο·?*.

EXAMPLE 18 To 50 ml. of dimethylformamide in a dry round-bottom flask is added 3.12 g. of 4-pyridyl£ormimidoylglycyl-D-phenylglycine. The resulting solution is cooled to -15’C. and treated with 1.08 g. of ethyl chloroformate. This reaction mixture is allowed to stir in the cold for 15 min. 6-Aminopenicillanic acid (2.25 g.) is slurried in 20 ml, of dimethylformamide and treated with 1.08 g. of chlorotrimethylsilane. To the resulting solution is added 1.01 g. of triethylamine, resulting in a precipitate of triethylamine hydrochloride. The mixture is cooled to ~104C. and added to · the solution of the mixed anhydride. The resulting reaction is further cooled to -25*C. and allowed to stir for one hour. The red solution is allowed to warm to room temperature over a 2 hr. period.

Water (20 ml.) is.added to the reaction mixture and the volume concentrated in vacuo to 1/3 to 1/2, and the residual solution treated with 300 ml of methanol. The diluted solution is filtered and the filtrate allowed to stir overnight (21 hrs.). The crystallized 6-[D-2-pheny1-2-(4-pyridylformimidoylaminoacetamido)acetarnido]penicillanic acid is filtered and dried, 2.24 g.

It is identical with the product from Example 1 in all respects. ' In a manner similar to Example 18, 4-pyridylformimidoylglycyl-D2fi| phenylglycine ethoxyformic anhydride can be replaced by the corresponding methoxyformic, .i-propoxyformic and pivalic anhydrides with comparable results. n<> 7 A EXAMPLE 19 To a slurry of 3.12 g, Of 4-pyridylfotmimidoylglycyl-D-phenvlglycine in 40 ml. of. dimethylformamide cooled to -20°C. is added 1.0 g. of N-methylmorpholine followed by 1.2 g. of thionyl chloride. The resulting clear solu5| tion is stirred for 45 min. at -15 to -20°C., and is subsequently treated wich 2.16 g. of 6-aminopenicillanic acid in 20 ml. of water, 10 ml. of dimethylformamide at pH. 7.8. After allowing the reaction mixture to stir for 10 min. at -10°C., ic is allowed to warm to room temperature. High-pressureliquid-chromatography of the solution indicates a yield of 335 mg. of 6-(D-210· pheny1-2-(4-pyridylfotmimidoylaminoacetaraido)acetamido]penicillanic acid (6.52 yield).

EXAMPLE 20.

The procedure of Example 19 is repeated for the preparation of 4pyvidylformimidoylglycyl-D-phenylglycyl chloride. The 6-aminopenicillanic |. acid is replaced by the addition of the indicated 6-aminopenicillanic acid derivative, and the reaction is conducted under che conditions of the indicated example to provide the desired product 6-[D-2-phenyl-2-(4-pyridylforraimidoylaminoacetamido)acetamido]penicillanic acid. ΰ ZO?a ' ,, 3q, h28v_/V CH3 tiJS 0 co,z Reaction Conditions z Example # (CH3O)2P- 3 (n-C3H7)2P- 3 (c6h5)2p- 3 3' ,5'-(t-C4Hg)2-4-HOC6H2CH2- 5B c6h5c°ch2- 7 ch3coch2- 7 ncch2- 7 CH3O2CCH,- 7 CH3CH2COCH2- 7 (CH3)2CHCOCH2- 7 CH3(CH2)2OzCCH2- 7 CgHgCH-N- 9 CH3CH’N- 9 C2H5CH»N- 9 n-C3H7CH»N- 9 (n-C4Hg)3Sn- 11 (CH3)3Sh- 11 (C2H5)3Sn- 11 (l-C4H9)3Sh- 11 (s-C4H9)3Sh- 11 (n-C3H7)3Sn- 11 £-CH30C6H4CH2- 13 (CH3)3C- 13 £-CH3OC6H4C(CH3)2- 13£-o2ng6h4ch2- 13 (c6h5)2ch- 13£-O2NC6H4CH(CH3)- 13 CC13SH2- 15 ICH2CH2“ 15 Br3CCH2- 15 Br2CHCH2- IS a j 7 EXAMPLE 21 To a suspension of 3.12 g. of 4-pyridylformimidoylglycyl-D-phenylglycine in 40 ml. of l-methyl-2-pyrrolidone cooled to -20°C. is added 1.0 g. of N-methylmorpholine followed by 1.2 g. of thionyl chloride. . The resulting bi clear solution is allowed to.stir at -15 to -20’C. for 45 min. . 6-Aminopenicillanic acid (2.25 g.) is slurried in 20 ml. of 1-methyli2-pyrrolidone and created with 1.08 g. of chloro trimethylsilane. To the resulting solution is· added 1.01 g. of triethylamine, resulting in a precipitate of trie thy latnine hydrochloride. The mixture is cooled to -10°C. and [l added, to the solution of the 4-pyridylformimidoylglycyl-O-phenylglycyl chloride. The resulting reaction-mixture is further cooled to -25°C. and allowed to stir for one hour, and then allowed to warm to room temperature. j Water (20 ml.) is added and the volume of the hydrolyzed mixture reduced in vacuo to 1/2. The residual solution is treated with 300 ml. of 15j| methanol. The precipitated 6-[D-2-phenyl-2-(4-pyridylformimidoylaminoacetamido)acetamido]penlcillanic acid, which is filtered and dried, is identical to the product of Example 1.

EXAMPLE 22 A solution of 3.12 g. of 4-pyridylformimidoylglycyl-D-phenylglycine in 30 ml. of dimethylformamide is cooled to -15°C. and treated with 1.18 g. of ethyl chloroformate. After stirring for 15 min. 1.15 g. of N-hydroxy5' succinimide is added and the solution allowed to warm to room temperature.

I The reaction mixture is diluted with 60 ml. of diethyl ether, and the Nhydroxysuccinimide ester hydrochloride allowed to crystallize. The interme- ι diate product 'is filtered and washed with cold ether.

A solution of 3.5 g. of ester hydrochloride in 40 ml. of dimethyl10 formamide is treated with 2.16 g. of 6-aminopenicillanic acid, and the resulting slurry treated with 850 mg. of pyridine. The reaction mixture is stirred at -10°C. for 30 min. and then allowed to stir at room temperature forj 2 hrs. The reaction is diluted with 200 ml. of methanol and the pH adjusted to 5.5 with dilute hydrochloric acid. The resulting precipitate, which is If filtered and dried in vacuo, is identical with the product of Example 1. ¢3072 EXAMPLE 23 A solution of 3.12 g. of 4-pyridylformimidoylglycyl-D-phenylglycine in 40 ml. of dimethylformamide is treated with 1.35 g. of 1-hydroxybenzotriazole, followed by 2.10 g. of dicyclohexylcarbodiimide. The solution is cooled ' to 0°C. and 2.16 g. of 6-aminopenicillanic acid and 1.1 g. of triethylamine in 25 ml. of dimethylformamide is added. The reaction mixture is allowed to stir for one hour in the cold and then allowed to warm to room temperature.

I After stirring ac room temperature fot one hour, the mixture is hydrolyzed with 50 ml. of water. The precipitated urea is filtered and the filtrate lcji diluted with 200 ml., of methanol. The solution is adjusted to pH 5.5 with ! dilute hydrochloric acid, and the precipitate which forms on standing is filtered and dried in vacuo. The product is identical to that formed in Example - 40 EXAMPLE 24 To 3.12 g. of 4-pyridylformimidoylglycyl-D-phenylglycine in 30 al. of l-methyl-2-pyrrolidone cooled to -15’C. is added 1.18 g. of ethyl chloroformate. After stirring in the cold for 15 min., 1.8 g. of N-hydroxyphthal51 imide is added and the solution allowed to warm to room temperature. Diethyl ether (60 ml.) is added, and the precipitated ester hydrochloride intermediate is filtered and dried.

A solution of the ester hydrochloride (4.57 g.) in 45 ml. of l-methy]} 2-pyrrolidone cooled to O’C. is treated with 2.16 g. of 6-aminopenicillanic acid and 850 mg. of pyridine. The mixture is stirred in the cold for one hour and then gradually allowed to warm to room temperature. After 30 min. the pH is adjusted to 5.5 and the solution diluted with 225 ml. of methanol. The product, which is filtered and dried in vacuo, is the same as that isolated in Example 1.

EXAMPLE 25 The 4-pyridylformimidoylglycyl-D-phenylglycine derivative employed and isolated in Examples 22, 23 and 24 are prepared and coupled with the following 6-am3.nopenicillanic acid derivatives, employing the reaction conditions of the indicated example to give the product of Example 1: O'? 3 icj I· 2θ! ! (ch3o)2p(n-C3H7)2PCc6h5)2p3 ’, 5 ’ - (t-C^Hg) 2-4' -HOC6H2CH2· CgH-COCH,CH COCHZncch2CH302CCH2CH3CH2COCH,(CH3),CHCOCH,CH3(CH2)2Q2CCH2. CgHjCH’N,CH3CH’NC,HSCH=Nn-C3H7CH=N= (n-C^HgljSh(CH3)3SnCc2h5)3s„3SnC^—C^Hg)3Sn(n-^H^JjSa£-CH3OC6H4CH2(ch3)3c£-ch3oc6h4c(ch3)2£-O2NC6H4CH2<c6h5)2ch2-02nc6r4ch(ch3)CCLjCHjich2ch2Br3CCH2Br2CHCH2Reactlon Conditions Example !t SB IS IS - 42 EXAMPLE 26 To a slurry of 2.25 g. of 6-aminopenicillanic acid in 20 ml..of dimethylformamide is added. 1.08 g. of chloro trimethylsilane followed by 1.01 g. of triethyl amine. The reaction mixture is cooled to -10’C. and 3.5 g. of 45 pyridylformimidoylglycyl-D-phenylglycine N-hydroxysuccinimide ester hydrochloride, prepared by the procedure of Example 22, in 35 ml. of dimethylformamide is added. The resulting reaction mixture is further cooled to -20°C. and allowed co stir for 2 hrs., and Is then stirred at room temperature for one hour.

Water (20 ml.) is added to the reaction mixture and to volume reduced under reduced pressure to 1/3. The residual solution is treated with 1 300 ml. of methanol, and the precipitated product filtered and dried. The 6- (D- 2-pheny 1-2- (4-pyridylf ormimidoylam.inoace tamido ] acetamido) penicillanic is identical to that of Example 1.

In a similar manner, the 1-hydroxybenzotriazole and N-hydroxyphthalimide esters of 4-pyrldylformimidoylglycyL-D-phenyIg.t.ycine, prepared in Examples 23 and 24, respectively, can be substituted for the N-hydroxysuccinimide of the present example with similar results.

I - 43 EXAMPLE 27 To a cooled (0°C.) solution of 5.04 g. of tri-n-butyltin e-aminopenicillinate and 3.12 g._ of 4-pyridylformimidoylglycyl-D-p.henylglycine in 50 ml. of dimethylformamide is added 2.10 g. of dicyclohexylcarbodiimide. The mixture is stirred for one hour in the cold, and then allowed to warm to room temperature, where it is Stirred for an additional 2 hrs. The resulting, reaction mixture is then treated with 1.6 g. of potassium thiophenoxide and allowed! to stir for one hour longer. The mixture is diluted with 20 ml. of water and the pH adjusted to 7.5. The insoluble urea is filtered'and the filtrate ad10 justed to pH 5.5 and diluted with 200 ml. of methanol. The product, which is filtered and dried, is identical with that obtained in Example 1.

Similar results are obtained when M,N-bis(morpholinoethyl)carbodiimide is used in place of dicyclohexylcarbodiimide in the procedure of Example 27, - 44 -·» EXAMPLE 28 Starting with 4-pyridylformimidoylglycyl-D-phenylglycine and either dicyclohexylcarbodiimide or N,N-bis(morpholinoethyl)carbodiimide, the procedure of Example 27 is repeated employing, in place of tri-n-butyltin 6-aminopeni5 cillinate, the indicated 6-aminopenicillanic acid derivative and using the work-up procedure of the indicated example, to provide the desired product, 6-[D-2-phenyl-2-(4-pyridylformimidoylaminoacetamido)acetamidoJpenicillanic acid.

Reaction Conditions Z Example # • (ch3o)2p- 3 (n-C3H7)2P- 3 5 ^C6H5^2F_ 3 3',5'-(t-C4Hg)2-4-H0C5H2CH2- 5b CgHgCOCHj- 7 . ch3cogh2- 7 ncch2- 7 10 CH3O2CCH2- 7 GH3CH2COCH2- 7 (CH3)2CHC0CH2- 7 CH3(CH2)2O2CCH2- 7 CgHgCH=N- 9 15; CH3CH=N- 9 C2H5CH»N- 9 n-C3H7CH»N- 9 Cn.“C4Hg)3Sn- - 11 3)3Sh- 11 27 (C2H5)3Sn- 11 (i-C4Hg)3Sn- 11 (s-C4Hg)3Sn- 11 (2-C3H7)3Sn- 11 2-ch3oc6h4ch2- 13 2^ (ch3)3c- 13 ·; £-ch3oc6h4ccch3)2- 13£-o2nc5h4ch2- 13 (CgH5)2CH- 13 £-O2NCgH4CH(CH3)- 13 3(if cci3ch2- 15 . ich2ch2- 15 Br3CCH2- 15 Br2CHCH2- 15 H- 1 EXAMPLE 29 To a slurry of 2.25 g. of 6-aminopenicillanic acid in 20 ml. of dimethylformamide is added 1.08 g. of chloro trimethylsilane followed by 1.01 g. of triethyl amine. The reaction mixture is cooled to -10°C. and 3.12 g. of 45 pyridylformimidoyiglycyl-D-phenylglycine and 2-1 g. of dicyclohexylcarbodiimide: in 35 ml. of dimethylformamide is added. The ragulting reaction mixture is further cooled to -20°C. and allowed to stir for 2 hrs., and is then stirred at room temperature for one hour.

Water (20 ml.) is added to the reaction mixture, the precipitated dicyclohexylurea is filtered and the volume reduced under reduced pressure co 1/3. The residual solution is treated with 300 al. of methanol, and the precipitated product filtered and dried. The 6-[D-2-phenyl-2-[4-pyridyl£ormirni~ doylaminoacetamido]aeetamido)penicillanic is identical to chat of Example 1.

In a similar manner, N,N-bis(morpholinoethyl)carbodiimide c«n be substituted for the dicyclohexylcarbodiimide of the present example wich similar results·. ·· 47 a a 3 EXAMPLE 30 A solution of 3.12 g. of 4-pyridylformimidoylglycyl-D-phenylglycine in 40 ml. of dimethylformamide is treated with 1.39 g. of p^nitrophenol, followed by 2.10 g. of dicyclohexylcarbodiimide. The solution is cooled to 0°C. and 2.16 g. of 6-aminopenicillanic acid and 1.1 g. of triethylamine in 25 ml. of dimethylformamide is added. The reaction mixture is allowed to stir for one hour in the cold and then allowed to warm to room temperature. After stirring at room temperature for one hour, the precipitated dicyclohexylurea is filtered and the mixture is diluted with 200 ml. of methanol. The solution ' is adjusted to pH 5.5 with dilute hydrochloric acid, and the precipitate which forms on standing is filtered and dried in vacuo. The product is identical to that formed in Example 1.

EXAMPLE 31 That portion of the procedure of Example 30 for the preparation of the 4-pyridylformimidoylglycyl-D-phenylglycine ester is repeated employing che appropriate phenol or thiophenol indicated. This ester is coupled with the requisite 6-amiaopenicillanic acid derivative under the acylation and work-up conditions of the indicated example to give the desired product, 6-[D-2phenyl-2-iC4-pyridylformimidoylaminoacetamido)acetamido]penicillanic acid. - 48 H,N S ch3 I CH3 c-o-z II 0 HN I /NHCH,CONHCHCOX I iO Z X Reaction Conditions Example # (ch3o)2p- c6h5o- 3 (ch30)2p- 2-C5H4NS- 3 (n-C3H7)2P- 4-ClC6H40- 3 (c6h5)2p- 4-ClC6H4S- 3 (c6hs)2p- 4-N02C6H4S- 3 3',5'-(t-C4Hg)2- 4-H0C6H2CH2- 4-ClC6H4O- 5B ‘ C,HcCOCH_6 5 2 w- 1 CgHgCOCH,- 4-NO2C6H4S- 7 ch3coch2- 4-N02C6H4S- 7 CH3C0CH2- 2-CcH,NS5 4 7 CH3C0CH2- 4-NO2c6H4°- 7 ncch2- 4-ΝΟ2Ο6Η4θ- 7 CH302CCHz“ c6h5s- 7 ch3o2cch2- 2-CsH4NS“ 7 ch,ch,coch7- 4-ClC^O- 7 ch,ch7coch7- 4-ClC6H4S- 7 (ch,)?chcoch,- 4-ClC,H.S6 4 7 (ch,),chcoch7- 4-N02C6H40- 7 CH3(CH2)2O2CCH2- c6h5o- 7 CH3(CH2)2O2CCH2-W- 7 C,H-CHeN6 5 c6h5s- . 9 C2H5CH«N- 4-ClC6H4S- 9 C,HsCH»N- 4-Ν0206ΗλΟ- 9 (Continued. . . ) 07 3 (Continued. . .) Z X Reaction Conditions Example ;f 4-ClCgH4O- 11 5 (CH3)gSn- . 4-ClCgH4O- 11 . (i-C4H9)3Sk- CgHss- 11 - (n-C3Hy)3Sn- CgH5S- 11 (n-C3H7)3Sn- CgHgO- 11 £-CH3OCgH4CH2- 4-ClCgH4S- 13 10 £-CH3OCgH4CH2- 2-C5H4NS- 13 (ch3)3c- 4-NO2CgH4O- 13 £-CH30CgH4C(CH3)2- 4-ClCgH4S- 13£-no2c6h4ch2- 4-N02CgH40- 13 · (CgH5)2CH-C5H5°- 13 15' £-NO2CgH4CH(CH3)- CgH5O- 13 cci3ch2- 4-ClC,H.O6 4 15 cci3ch2- 4-ClCgR4S- 15 CCIjCHj- 4-N°2CgH4S- 15 xch2ch2- CgHgO- 15 20 Br3CCH2- 2-C5H4NS- 15 Br2CHCH2- 4-ClCgH40- 15 - 50 EXAMPLE 32 To a slurry of 4.5 g. of 6-aminopenicillanic acid in 40 ml. of dimethylformamide is added 1.28 g. of dichloro dimethylsilane followed by 2.02 g of triethyl amine. The reaction mixture is cooled to -10°C. and 7.0 g. of 45 pyridylformimidoylglycyl-D-phenylglycine N-hydroxysuccinimide ester hydrochloride, prepared by the procedure of Example 22, in 70 ml. of dimethylformamide is added. The resulting reaction mixture is further cooled to -20°C. and allowed to stir for 2 hrs., and is then stirred at room temperature for one hour.

Hater (40 ml.) is added to the reaction mixture and to volume reduced under reduced pressure to 1/3. The residual solution is treated with 600 ml. of methanol, and the precipitated product filtered and dried. The 6-[D-2-pheny1-2-[4-pyridyIformimidoylaminoacetamido]acetamido)penicillanic is identical to that of Example 1. - 51 EXAMPLE 33 A suspension of 4.2 g. of 6-aminopenicillanic acid saccharimide hydrochloride in 50 mi. of dimethylformamide is treated with 1.01 g, of triethylaminA and the solution cooled to -5°C. To this solution is added 4-pyridylformimi3’ doylglycyl-D-phenylglycine ethoxyformic anhydride as prepared in Example 5A over a period of 5 minutes. The reaction mixture is allowed to stir In the cold for 30 minutes, and is then treated with S40 mg. of sodium bicarbonate in 10 ml. of water. After stirring at room temperature, the reaction pH is adjusted to 5.5 with’dilute hydrochloric acid. The volume .of the reaction is If. concentrated in vacuo to about 60 ml. and 200 ml. of methanol is added. The precipitate which forms on standing is filtered and dried to give 6-[D-2-phenyl!2-(4-pyridylformimidoylaminoaceeamido)acetamido]penicillanic acid, identical to that from Example 1.

EXAMPLE 34 ‘ΐ δ ο 7 The procedure of Example 33 is repeated, substituting for 4-pyridylformimidoylglycyl-D-phenylglycine ethoxyformic anhydride che following mixed anhydride prepared from Examples 2 and 4, to give the desired product, 6-[D-25 phenyl-2-(4-pyridylformimidoylarninoacecamido)acetamido]penicillanic acid: 4-pyridylformimidoylglycyl-D-phenylglycine pivalic anhydride; 4-pyridylformimidoylglyeyl-D-phenylglycine methoxyformic anhydride; 4-pyridylformimidoylglycyl-D-phenylglycine .i-propoxyformic anhydride; and 4-pyridylformimidoylglycyl-D-phenylglycine n-butoxyformic anhydride. - 53 4» Qi' EXAMPLE 35 To a slurry of 3.12 g. of 4-pyridylformimidoylglycyl-D-phenyLglycine in 40 ml. of dimethylformamide cooled to -20°C. is added 1.0 g. of N-methylmorpholine followed by 1.2 g. of thionyl chloride. The resulting solution is ' allowed to stir for 45 minutes at -15 to -20°C., and is then allowed to warm to -5°C.

A suspension of 4.2 g. of 6-aminopenicillanic acid saccharimide hydrochloride in 50 ml. of dimethylformamide is treated with 1.01 g. of triethylamine, cooled to -5°C. and added over a 5 minute period to the above acid. 1Q.; chloride. The resulting reaction mixture is allowed to stir at -5°C. for 30 minutes. Sodium bicarbonate (840 mg.) in 10 ml. of water is added to the reaction mixture and the resulting solution allowed to stir at room temperature for 3 hours. The pH is adjusted to 5.5 by the addition of dilute hydrochloric acid and the vdlume of the solution concentrated under reduced pres15i sure to about 60 ml. Methanol (200 ml.) is added and the solution allowed to stand at room temperature until crystallization ceases. The product, which isi filtered and dried, is identical with the product of Example 1. - 54 «807^ EXAMPLE 36 A solution of 3.5 g. of 4-pyridylformimidoylglycyl-D-phenylglycine NI hydroxysuccinimide ester hydrochloride, prepared by the procedure of Example 22, in 40 ml. of dimethylformamide is treated with 4.2 g. of 6-aminopenicillanic acid saccharimide hydrochloride, cooled to -5°C. and the resulting slurry treated with 1.7 g. of pyridine. Stirring in the cold is continued for 45 minutes, followed by the addition of 840 mg. of sodium bicarbonate in 10 ml. of water. After stirring at room temperature for 3 hours, the pH is adjusted to 5.5 with dilute hydrohcloric acid and 200 ml. of methanol is added. On standing, the product crystallizes and is subsequently filtered and dried.

The product, 6-[D-2-phenyl-2-(4-pyridylformimidoylaminoacetamido)acetamido]penicillanic aeid ia identical with that formed in Example 1.

Example 37 A solution of 3.12 g. of 4-pyridyl£oraitaidoylglycyl-D-phenylglycine in 40 ml. of dimethylformamide is treated with 1.35 g. of 1-hydroxybenzotriazole, followed by 2.10 g. of dicyclohexylcarbodiimide. The solution is cooled to -5’C. and 4.2 g. of 6-aminopenicillanic acid saccharimide hydrochloride and) 1.1 g. of triethylamine in 25 ml. of dimethylformamide is added. The reaction) mixture is allowed to stir for one hour in the cold and then allowed to warm 201' to room temperature. Sodium bicarbonate (840 mg.) in 30 ml, of water is added! ’ i and the reaction mixture allowed to stir for 3 hours. The precipitated dicyclohexylurea Is filtered and the filtrate adjusted to a pH of 5.5 Follow-1 ing concentration in vacuo to about 50 ml., 200 ml. of methanol is added, and the solution allowed to stand at room temperature. The product, after fil25 tration and drying, proved to be identical to the 6-[D-2-phenyl-2-(4-pyridylformimidoylaminoacetamido)acetamido]penicillanic acid of Example 1.

EXAMPLE 38 A solution of 4.57 g. of 4-pyridyIformimidoylglycyl-D-phenylglycine N-hydroxyphthalimide ester hydrochloride, prepared according to the procedure of Example 24, in 45 ml. of l-methyl-2-pyrrolidone cooled to -5°C. is created with 4.2 g. of 4-aminopenicillanic acid saccharimide hydrochloride followed by 850 mg. of pyridine.. After stirring at -5°C. for 45 minutes, the mixture is allowed to warm to room temperature. Sodium bicarbonate (840 mg.) in 10 ml. of water is added and the reaction mixture allowed to stir for an additional 3 hours, the pH is adjusted to 5.5 and 200 ml. of methanol Is added, the lol precipitate which forms, when filtered and dried, is identical to the 6—[D—2— phenyl-2-(4-pyridyIformimidoylaminoacetamido)acetamido]penicillanic of Example 1.

EXAMPLE 39 To a cooled (-50C.) solution of 4.2 g. of 6-aminopenicillanic acid ΐγ saccharimide hydrochloride, 3.12 g. of 4-pyridylformimidoylglycyl-D-phenylglycine and 1.01 g. of triethylamine in 50 ml. of dimethylformamide is added 2.10 g. of dicyclohexylcarbodiimide, and the reaction mixture allowed to stir in the cold for 45 minutes, the mixture i3 allowed to warm to room temperature followed hy the addition of 840 mg. of sodium bicarbonate in 20 ul. of 2(j water. The precipitated dicycloheXyluren is filtered and the filtrate concentrated to about 45 ml. The pH is adjusted to 5.5 and 200 ml. of methanol is added. The product, which is filtered and dried, is identical to the 6[D-2-phenyl-2(4-pyridylformimidoylaminoacetamido)acetamido]penicillanic acid of Example. 1» - 56 EXAMPLE 40 A solution of 3.12 g. of 4-pyridylformimidoylglycyl-D-phenylglycine in 40 ml. of dimethylformamide is treated with 1.39 g. of £-nitrophenol, followed by 2.10 g. of dicyclohexylcarbodiimide. The solution is cooled to -5°C. ' and 4.2 g. of 6-aminopenicillanic acid saccharimide hydrochloride and 1.1 g. of triethylamine in 25 ml. of dimethylformamide is added. The reaction mixture is allowed to stir for one hour in the cold and then allowed to warm to room temperature. After stirring at room temperature for 3 hours with 840 mg. of sodium bicaronate in 10 ml. of water, the precipitated dicyclohexylurea is filtered and the mixture is diluted with 200 ml. of methanol. The solution is adjusted to pH 5.5 with dilute hydrochloric acid and the precipitate which forms on standing is filtered and dried in vacuo. The product is identical to that formed in Example 1.

EXAMPLE 41 That portion of the procedure of Example 40 for the preparation of the 4-pytidylformimidoylglycyl-D-phenylglycine ester is repeated employing the appropriate phenol or thiophenol indicated. This ester is coupled with the requisite 6-aminopenicillanic acid saccharimide derivative under the acylation andworx-up conditions indicated to give the desired product, 6-[D-2-phenyl2-(4-pyridyIformimidoylaminoacetamido)acetamidoJpenicillanic acid. '1 4-ClCgH^Oc6h5oC6H5S4-C1C.H.SO 4 2-CjH^NS-

Claims

CLAIMS:

1. A process for the preparation of a compound of the formula: which comprises contacting a compound of the formula: wherein X is chloro, phenoxy, 4-chlorophenoxy, 4-nitrophenoxy phenylthio, 4-chlorophenylthio, 4-nitrophenylthio, 2-pyridylthio, N-phthalimidoxy, N-succinimidoxy, 1-benzotriazoloxy, -0-C(=NR')NHR wherein R^ and R are eaeh eyclohexyl or 10 N-morpholinoethyl, or R-^-0- wherein R is selected from alkoxy having from one to four carbon atoms and t-butyl, with a 6-aminopenicillanic acid of the formula: wherein Z is hydrogen or a blocking moiety, in a reaction15 inert solvent at a pH of 3.5 - 8 and reaction temperature of 0 to -15°c, followed if necessary by removal of the blocking moiety J5. - 59 5

2. A process according to claim 1, wherein the blocking moiety Z is selected from ' / a) -P wherein R^ and R 2 are eac b selected from alkyl having one to three carbon atoms, alkoxy having one to three carbon atoms and phenyl; b) 3,5-di-t-butyl-4-hydroxybenzyl; θ » o) -CH 2 ~Y wherein ϊ is selected from -C-Rg wherein R^ is selected from phenyl and alkyl having one to three carbon atoms, -CN and carboalkoxy having two to four carbon atoms; d) -N=CH-R^ wherein R^ is selected from phenyl and alkyl having one to three carbon atoms; e) -Sh(R 5 ) 3 wherein R g is alkyl having one to four carbon atoms; f) -CR,R_R„ wherein R, and R_ are each selected from 6 7 8 6 7 hydrogen, phenyl and methyl and Rg is selected from phenyl, 4-methoxyphenyl, 4-nitrophenyl and methyl, provided that when R g and Ry are each methyl, Rg is also methyl; 20 g) -CH 2 CRgR^ 0 R 13 wherein R g is selected from bromo, chloro and iodo and R-^θ and R 11 are each selected from hydrogen, bromo, chloro and iodo; and h} -Si(CH 3 ) 2 R^ 2 wherein R 32 is selected from methyl and 6- aminopenicillanoyloxy. 25

3. The process of olaim 1 wherein R is ethoxy, Z is hydrogen, the reaction-inert solvent is l-methyl-2-pyrrolidone and the reaction temperature is -1O°C. 60 42072

4. The process of claim 2 wherein R is ethoxy, Z is the blocking Z R 1 moietv -P wherein R. and R, are each methoxv, the reaction-inert solvent ' Xr 2 is dimethylformamide and the reaction temperature is O’C.

5. The process of claim 4 wherein the blocking moiety Z is removed by aqueous hydrolysis.

6. The process of claim 2 wherein R is ethoxy, Z is the blocking moiety 3,5-di-t i -butyl-4-hydroxybenzyl, the reaction-inert solvent is dimethylformamide and the reaction temperature is -10’C.

7. The process of claim 6 wherein the blocking moiety Z is removed by aqueous hydrolysis at a pH of about 8.

8. The process of claim 2 wherein R is ethoxy, Z is the blocking II noiety -CH^-Y wherein t is -C-Rg wherein R^ is phenyl, the reaction-inert solvent is dimethylformamide and the reaction temperature is -10’C.. *

9. The process of claim 8 wherein the blocking moiety Z is removed with potassium thiophenoxide.

10. The process oE claim 2 wherein R is ethoxy, Z is the blocking moiety -N-CHR^ wherein R^ is phenyl, the reaction-inert solvent is dimethylformamide and the reaction temperature is O’C.

11. The process of claim 10 wherein the blocking moiety Z is removed with sodium iodide.

12. The process of claim 2 wherein R is ethoxy, Z is the blocking moiety -Sn(Rg) 3 wherein Rg is n-butyl, the reaction-inert solvent is dimethylformamide and the reaction temperature is -5’C.

13. The process of claim 12 wherein the blocking moiety Z is removed with potassium thiophenoxide.

14. The process of claim 2 wherein R is ethoxy, Z is the blocking moiety -CRgR^Rg wherein Rg and R? are each hydrogen and Rg is £-methoxyphenyl, the reaction-inert solvent is dimethylformamide and the reaction temperature is -10°C.

15. The process of claim 14 wherein the blocking moiety Z is removed' by acid hydrolysis with hydrofluoric acid.

16. The process of claim 14 wherein the blocking moiety Z is removed by catalytic hydrogenation.

17. The process of claim 2 wherein R is ethoxy, Z is the blocking inert solvent is dimethylformamide and the reaction temperature is -5°C.

13. The process of claim 17 wherein the blocking moiety Z is removed by electrolytic reduction.

19. The process of claim 2 wherein R is ethoxy, Z is the blocking 15 moiety -SifCHg/jR^ wherein R^ is CH^, the teaction-inert solvent is dimethylformamide and the. reaction temperature is -10°C.

20. The process of claim 19 wherein the blocking moiety Z is removed by aqueous hydrolysis.

21. A process for the preparation of a compound of the formula: NH co 2 H - 62 which comprises contacting a compound of the formula.' NH 0 C-NHCH.CONHCH-C-X wherein X is chloro, phenoxy, 4-chlorophenoxy, 4-nitrophenoxy, phenylthio, 4chloropheny1thio, 4-nitrophenylthio, 2-pyridylehio, N-phthalimidoxy, N-succiniI II ( II midoxy, 1-benzotriazoloxy, -O-C(”NR )NHR wherein R and R are each cyclohexyl It 5 or N-morpholinoethyl, or R-C-O- wherein R is selected from alkoxy having one to four carbon atoms and t-butyl, with a 6-aminopenicillanic acid of the formula: in a reaction-inert solvent and reaction temperature of -10 to -5°C., followed by aqueous hydrolysis of the saccharimide group at a pH of 88-5' 0 II

22. The process of claim 21 wherein X is R-C-O- wherein R is ethoxy, the reaction-inert solvent is dimethylformamide and the reaction temperature is -5°C. wherein Z is selected from -PR 3 R 2 wherein R^ and R 2 are each selected.? from alkyl having one to three carbon atoms, alkoxy having one to three carbon atoms and phenyl?

3. ,5-di-t-butyl-4-hydroxybenzyl; -GBL-Y wherein Y is selected from -C-R 3 wherein R 3 is selected from phenyl and alkyl having one to three carbon atoms, -CN and carboalkoxy having two to four carbon atoms; -N=CHR 4 wherein R^ is selected from phenyl and alkyl having one to three carbon atoms; -Sn(Rg) 3 wherein Rg is alkyl having one to four carbon atoms? -CRgR^Rg wherein Rg ahd R? are each selected from hydrogen, phenyl and methyl and Rg is selected from methyl, phenyl, 4-methoxyphenyl and 4nitrophenyl, provided that when R g and R? are each methyl, Κθ is also methyl; -CHjCRgR-^R^ wherein R g is selected from bromo, chloro and iodo and R^ Q and R^ are each selected from hydrogen, bromo, chloro and iodo; and Si(CH 3 ) 2 R 12 wherein R.^2 selected from methyl and 6-aminopenioillanoyloxy. - 64 *3073

24. A compound of claim 23, formula I, wherein Z is -PR 1 R 2 wherein R^ and R 2 are each alkoxy having one to three carbon atoms.

25. The compound of claim 24 wherein R^ and R 2 are each methoxy.

26. The compound of claim 23, formula I, wherein Z is 3,5-di-t-butyl-4-hydroxybenzyl. 0 II

27. The compound of claim 23, formula I, wherein Z xs -CHgCRg wherein Rg is phenyl.

28. The compound of claim 23, formula I, wherein Z is -N=CHR 4 wherein R^ is phenyl.

29. The compound of claim 23, formula I, wherein Z is -Sn(Rg)g wherein Rg is n-butyl.

30. A compound of claim 23, formula I, wherein Z is -CR g R 7 Rg wherein Rg and R 7 are each Selected from hydrogen, phenyl and methyl.

31. The compound of claim 30 wherein Rg and R 7 are each hydrogen and R g is phenyl.

32. A compound of claim 23, formula I, wherein Z is -CH^CRgR^QR^^ wherein R lo and R^^ are each selected from hydrogen, bromo, chloro and iodo.

33. The compound of claim 32 wherein Rg, R 10 and R^^ are each chloro.

34. The compound of claim 23, formula I, wherein Z is -Si(CHg)3.

35. The compound of claim 23, formula II.